A. Technical Field
The present subject matter is directed to methods and apparatuses for applying binding agents, topper agents, or other chemical product for the purpose of ensuring dust losses in transit are not more than a determined limit and achieve dust mitigation and suppression for cargo and other transported materials in material handling systems, such as without limitation, any means of container conveyance, such as trucks, barges, railroad cars, conveyor belts, or otherwise. The present subject matter is directed to methods and apparatuses for applying binding agents, topper agents, or other chemical product for the purpose of ensuring coal and coal dust losses in transit are not more than a determined limit and achieve coal dust mitigation and suppression for coal being transported in railroad cars and delivered to coal burning utilities, transfer terminals and facilities, export terminals and ports and other destinations.
B. Description of Related Art
Coal destined for domestic or international market is mined and loaded into open top gondola railway cars at the mine sites. The open top gondola cars expose the top surface of the coal pile to rain, wind, sun, and scouring air resistance as the train travels from the mine to the unloading facility. At the mines, a binding topper agent normally is applied to the surface of the loaded coal immediately after the loading operation. The binding topper agent serves to counteract the air scouring effect on the coal pile and minimize product lost from the cars on route. Various chemical formulations are used as the binding topper agent. Cost, travel distance, coal particle distribution, top of car profile, and climactic conditions influence the binding agent selection and concentration. The effectiveness of the mine-applied binding topper agents appears affected by coal settlement and movement within the railroad car, which occurs within the first several hundred kilometers of travel on route to unloading. There is possible need to also apply binding topper agent at a second location between the mine site of the rail car loading and the final destination where the coal will be unloaded.
It is sometimes desirable to be able to apply large volumes of a fluid, such as, and without limitation, a binding agent, to cargo in, or on, one or more railcars, trucks, barges, or other conveyances while avoiding unintended application or dispensing of the fluid between conveyances or on any of the personnel safety equipment of the conveyances or on operative components connecting the conveyances, or to the surrounding environment or workers, or anywhere else except the cargo. Such unintended application or dispensing of the fluid may be undesirable for any number of reasons but may include the desire to avoid wastage of the fluid.
It is sometime desirable to be able to dispense large volumes of a binding agent very quickly but to pause and restart dispensing operations frequently and with high precision and high accuracy. A non-limiting example of a dispensing operation in which it may be desirable to dispense large volumes of a binding agent very quickly but to pause and restart dispensing operations frequently and with high precision is application of an effective amount of a binding agent to the cargo in multiple open top gondola railway cars in a moving train.